The purpose of this grant is to understand how temporal information processing affects learning. Temporal factors affect the speed of learning and how that learning is expressed. The experiments proposed here analyze the specific ways in which the temporal pattern of events affects associative learning. The studies analyze how events are integrated or segregated into different memory representations and how these representations are used to determine response strength, choice and inference. The studies will lead to a better understanding of learning and, more specifically, of how one learns to anticipate predictable events. There are deficits in timing and anticipation in many behavior disorders. Depression, schizophrenia, and attention-deficit-hyperactivity disorder are all associated with distortions in time perception and changes in the capacity to anticipate predictable events. Drug taking and other habitual high risk behaviors are associated with a diminished capacity to anticipate long-term consequences. An understanding of the mechanisms of anticipatory learning will lead to more effective behavioral and biological treatments.